Agent for recovery of volatile solvents and method of using it



Patented Nov. 29, 1927.

UN i 5 WALTER RUNGE, OF ORANGE, NEW JERSEY, ASSIGNOR TO THE BREGEAT CORPORA- TION OF AMERICA, OF NEW YORK, N. Y., A. CORPORATION OF DELAWARE.

AGENT FOR RECOVERY OF VOLATILE SOLVEN TS AND METHOD OF USING IT.

No Drawing.

The invention relates to an agent to be used for the recovery of volatile solvents and particularly to an agent of this char acter which is adequate and eliicient with reference to the recovery of volatile material such as gasolene. The object of the invention is to obtain important results in the recovery of volatile matter by the use of a special agent for its recovery, said agent having a great capacity for absorbing volatile material.

The recovery of volatile solvents is now conducted in its most efficient development, in accordance with a process invented by J. H. Bregeat and described by him in his Patent No. 1,315,700 of September 9, 1919. In conducting the Bregeat process it is common practice to bring a phenolic or cresolic oil and gas containing gasolene into contact with each other at temperature of approximately 7 0 to F. Should either the absorbing medium or the gas be at higher temperatures, artificial cooling is resorted to. It is endeavored to operate the process at as low pressure as possible, but due to the back pressure caused by resistance to vari- 0115 parts of the apparatus, the pressure may at times reach 40 inches of water. The etficiency of the Bregeat process depends upon the discovery of the peculiar and special properties of phenolic and cresolic material as absorbents for volatile solvents. It has, however, been found that these Bregeat absorbent-s, under certain conditions, can be economically supplemented by an oil ob tained from the tar from a carbonaceous material distilled at low temperature. Oil of this character is recommended particularly for use in connection with the recovery of hydrocarbons of the gasolene type.

The material which constitutes the subject matter of this application and which furnishes the agent in those cases where the volatile solvents are of the character that they can be more satisfactorily dealt with than by the use of cresols or phenols is the oil derived or distilled from low temperature tar. Low temperature tar is the distillate from coal or carbonaceous material recovered under conditions such that the gas evolved does not pass through a temperature zone, say in excess of 1,000 or 1,200 F. and frequently lower. The result of coal distil lation carried on under these conditions is a tarry mass known as low temperature tar.

Serial N0. 692,173.

This tar, when distilled, will yield a mixture of oils and a pitch residue. These oils can be fractionally distilled or collected as a mixture and may be used as such or they may then be treated chemically for removal or recovery of tar acids, i. e., the phenolic and cresolic materials. The remainder of the oils may either be distilled or used as such for the purposes of this invention. These oils are rich in naphthenes and generally contain in addition a variety of partially saturated hydrocarbons. It is believed that it is due to the presence of naphthenes that the oils derive their special absorbing property when employed for the recovery of volatile solvents. The oils furthermore are relatively inexpensive.

When oils of this character are used for the recovery of say gasolene, the atmosphere or gaseous mixture of which the gasolene to be recovered forms a part, is conducted into a scrubbing tower in which it comes into contact with the oil. Preferably the tower is arranged on the counter-current principle. The result of this treatment is that the oil absorbs the gasolene from the gas mixture. The oil is then heated either directly or indirectly, preferably in another vessel or tower and thereby releases the absorbed gasolene, which is then recovered by condensation. The oils, freed from the absorbed gasolene, are cooled and are ready for momployment.

This process may be conducted at any pressure. It can be put into practice either directly at gas wells for the treatment of the casing head gases and is also available in industrial processes of a large variety wherein during the course of operations evaporation of gasolene occurs or other volatile solvents.

I claim:-

1. An agent for the recovery of volatile solvents, consisting of distillation products from low temperature tar and containing the naphthene and the partially saturated hydrocarbon distillates from such low temperature tar.

2. An agent for the recovery of volatile solvents, consisting of distillation products from low temperature tar, being relatively free from tar acids and containing the naphthene and the partially saturated hydrocarbon distillates from such low temperature tar.

3. In the art of recovering volatile solvents, that improvement which consists in scrubbing a gaseous mixture, containing the volatile solvents to be recovered, with distillation products of low temperature tar containing the naphthene and partially saturated hydrocarbon distillates' from such low temperature tar. 1

4. In the art of recovering volatile solvents, that improvement which consists in scrubbing a gaseous mixture, containing the volatile solvents to be recovered, with distillation products of low temperature tar, relatively free" from tar acids, containing the naphtliene and partially saturated hydrocarbon distillates from such low temperature tar.

5. The method of recovering hydrocarbons of the gaseous type from agas containing the same which comprises absorbing the gasolene material in oily distillates from low temperature tar containing naphthenes and partially saturated hydrocarbon distillates from such low temperature tar, and then distilling the absorbed hydrocarbons from the oil.

In testimony whereof I have hereunto set my hand.

WTER RUN GE. 

